1. Field of the Invention
The present invention relates to a communication apparatus, a communication continuation method, and a communication continuation program. More particularly, the present invention relates to a communication apparatus with reduced power consumption, and a communication continuation method and a communication continuation program executed in the communication apparatus.
2. Description of the Related Art
In recent years, MFP (Multi Function Peripheral) including printer, copier, and facsimile functions has to be driven only at the request for a process such as printing, copy, facsimile transmission/reception, and is on standby waiting for a request when no process is being executed. During standby, minimizing power consumption is desired while it is also desired to execute a process immediately in response to a request.
MFP is often connected with a network such as a local area network (hereinafter referred to as “LAN”) and includes a communication apparatus for connecting to the network. Reduction in power consumption is likewise desired in the communication apparatus.
When MFP is on standby and power supply to the communication apparatus is cut off in order to reduce power consumption, MFP cannot respond to access, for example, from a computer connected to the network. Therefore, the computer that has made access determines that MFP is powered off, and changes the settings of the network environment to a state in which MFP is not connected to the network. Therefore, Japanese Laid-Open Patent Laid-Open No. 2005-74928 discloses a data processing system including a data processing apparatus having a communication buffer for temporarily storing incoming external data, and at least one data transmission apparatus transmitting data to the data processing apparatus. The data processing apparatus includes a data-specifying information extracting means for extracting and holding data-specifying information from the incoming data in a power saving mode and a data retransmission request means for transmitting a retransmission request signal including the extracted data-specifying information to the data transmission apparatus when shifting to a normal mode. The data transmission apparatus includes a data retransmission means for receiving the retransmission signal to retransmit reception data specified by the data-specifying information included in the retransmission signal.
However, in the conventional data processing system, the data transmission apparatus changes the settings of the network environment to a state in which the data processing apparatus is not connected. Accordingly, in order for the data transmission apparatus to receive the retransmission request signal, a new process is required to return the settings of the network environment of the data transmission apparatus to the original settings. Moreover, when receiving the retransmission request, the data transmission apparatus has to retransmit data specified by the data-specifying information. Therefore, the same data is sent twice, so that the load on the data transmission request is increased and the network resource is wasted.